POROUS SILICON RELAXATION MEDIUM FOR DISLOCATION FREE CMOS DEVICES

摘要

A method for forming CMOS devices includes masking a first portion of a tensile-strained silicon layer of a SOI substrate, doping a second portion of the layer outside the first portion and growing an undoped silicon layer on the doped portion and the first portion. The undoped silicon layer becomes tensile-strained. Strain in the undoped silicon layer over the doped portion is relaxed by converting the doped portion to a porous silicon to form a relaxed silicon layer. The porous silicon is converted to an oxide. A SiGe layer is grown and oxidized to convert the relaxed silicon layer to a compressed SiGe layer. Fins are etched in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.

主权项

1. A method for forming complementary metal oxide semiconductor devices, comprising:
protecting a first portion of a tensile-strained silicon layer of a silicon on insulator substrate to dope a second portion of the tensile-strained silicon layer outside the first portion; growing an undoped silicon layer on the doped portion and the first portion, wherein the undoped silicon layer becomes a tensile-strained undoped silicon layer; relaxing strain in the undoped silicon layer over the doped portion by converting the doped portion to a porous silicon to form a relaxed silicon layer; converting the porous silicon to an oxide; and oxidizing a SiGe layer formed on the relaxed silicon layer to convert the relaxed silicon layer to a compressed SiGe layer.